AAAR 37th Annual Conference October 14 - October 18, 2019 Oregon Convention Center Portland, Oregon, USA
Abstract View
Comparing the RDG-FA and T-matrix Methods for Soot Given Information about Polydispersity and Effective Density
Keyhan Babaee, Timothy Sipkens, STEVEN ROGAK, University of British Columbia
Abstract Number: 894 Working Group: Carbonaceous Aerosol
Abstract This compares the optical properties of soot aggregates for non-premixed flames, calculated using Rayleigh-Debye-Gans approximation for fractal-like aggregates (RDG-FA) and the multiple-sphere T-matrix method. The techniques are evaluated, considering that the primary particle size and effective density are correlated with the aggregate mobility diameter. The distribution of primary particle size is characterized using a geometric standard deviation, which is a function of the aggregate mobility diameter. Primary particle size is assumed to be constant within each aggregate. For RDG-FA, we use the implementation described in Babaee et al. (2019); while, for the T-matrix method, the absorption and scattering cross-sections are interpolated from the database developed by Liu et al. (2019). As a case study, the current work selects a refractive index of 1.6+0.6j, 1.95+0.79j, and 2.0+1.0j at wavelengths of at 532 nm, 550 nm, 870 nm, respectively. The work proceeds with a parametric study to determine the sensitivity of the optical properties of the aggregate to the mass-mobility exponent, effective density, and parameters of the primary particle size distribution.